The Importance of Proper Cleanroom Maintenance
01 November 2021

The Importance of Proper Cleanroom Maintenance

When working in a cleanroom it is important to maintain a pristine, contaminant free, environment. The less well-kept a room is then the more likely it is harboring pollutants, which can distort the results of the work taking place within the room. Since these rooms are built to prevent contamination to an exceedingly small degree, not implementing a regular maintenance schedule can fundamentally interfere with the functionality of the room over a period of time. The best way to ensure your work space is pristine, is by creating a regular maintenance routine that is specific to your critical environment’s needs.

In this post we’ll take a look at why exactly this is so important, some ways to establish a regular maintenance schedule, and provide a general outline for thorough cleansing of all equipment within a cleanroom.

Why is maintenance so important?

Regular maintenance is vital to cleanrooms because without a maintenance plan, contaminants will accumulate and put all work within the environment at risk of being compromised. It's not just limited to physically cleaning a room, but also ensuring reliability and efficiency of equipment day to day. A thorough maintenance plan will reduce the potential amount of unplanned downtime due to breakdowns and faults. Preventative measures reduce this potential through regular checks of the equipment and the room itself. A regular plan prevents the buildup of dust, vapors, and other airborne particles which equipment and products are sensitive to. Not only is creating a schedule of regular maintenance for a room important, but so is the exact way that it occurs. In fact, even wiping up a mess improperly can be a potential source of contamination. We recommend using lint-free, disposable mop heads, non-shedding wipes, plastic or stainless steel buckets, as well as HEPA filter vacuums while cleaning your room. Always make sure that you have the specified equipment for your room as well. Improperly matched products in rooms can result in the introduction of microorganisms into your environment, effectively contaminating your cleanroom.

Day to Day Maintenance

The most effective way to ensure your room maintains its day to day cleanliness is to establish daily maintenance routines. Regular routines, while working, serve to clear the room from particles introduced by cleanroom staff. Every room has different requirements, but the following are some ways to control the human component. Before establishing guidelines in your own cleanroom, first make sure that they are appropriate for your specific requirements. The following rules have been assembled by Roger McFadden, Senior Scientists for Staples Inc, and are appropriate for a Class 1000 cleanroom.

Thorough approach to cleanroom maintenance and cleaning

In a previous blog, we detailed some of the most important aspects of cleanroom maintenance. Each room has its own procedures, which should be determined and agreed upon within your organization. Our suggestions are just that – suggestions. These are considered to be the best practices for cleanroom maintenance and can serve as general guidelines. Before beginning any cleaning be sure to check your cleaning products are appropriate for your specific controlled environment. Each class of cleanroom uses specific cleaning equipment and solvents. By not using the correct materials you put your room at risk to be cleaned ineffectively.

Since rooms are active 24/7, maintenance should be split into a few different primary actions – filter maintenance, equipment maintenance, and room maintenance. Let’s take a look at each aspects.

Filter Maintenance: Since air flows continuously through the filters in any cleanroom environment 24/7, it's important to change these on a regularly scheduled basis. Their heavy use causes them to be soiled much quicker than most equipment within the room. There are three distinct parts of the filter system that need to be maintained. First are the pre-filters, which need to be changed about six times a year. Next are the bag filters. These need to be changed out about once a year. Finally is the HEPA filter - the heavy lifter of the bunch. This needs to be changed out about once every three years or so. The first two filters need to be changed out more frequently, as their cleanliness helps to keep the HEPA filter protected. The HEPA filter is usually the most costly of these three, so it is important to make sure the other two are full functioning properly. It should be noted that these timelines may need to be accelerated depending on the location of the building. A system that has to filter out heavier higher levels of pollutants may need to be cleaned more frequently.

Equipment Maintenance: This refers to the machinery and equipment within the room. Equipment must be checked to ensure that it's working normally, and to do this may require a planned shutdown. With this in mind, it may be best to plan your filter and equipment maintenance together.

Room Maintenance: Room maintenance should be broken down into four different aspects, as rooms must be cleaned in a particular order to reduce the transfer of contaminants from one section to another. It is best practice to begin with the highest point of the room and work down. The order is ceilings, walls, surfaces, and then floors.

  • The ceiling should be cleaned from the top down - generally using extended handle tacky rollers. It may be necessary to wet mop the ceiling as well. This is usually accomplished with a self-wringing sponge or a flat mop, all with extendable handles. When doing this, make sure to use compatible solvents. These include Deionized water, Isopropyl alcohol, as well as disinfectants and cleanroom specific cleaners.
  • The walls should be cleaned using the hand wiping method parallel to the airflow of the room. It is best to use a dry, lint-free nonwoven or polyester knit cleanroom wipe. If needed, these can be combined with solvents. These are generally best as they are extremely low in particle generation and chemical extracts.
  • Surfaces should typically be cleaned with hand wipes. In some higher usage instances it is more convenient to implement wipe dispensers. Dispensers work to make the storage and distribution of wipes easy while still eliminating waste and cross contamination. In particular, using wipes with a pre-saturated with 70% isopropyl alcohol and 30% Deionized water are very effective for wet cleaning, when necessary. If ESD is a concern it is best to use wipes that employ carbon fibers within the knit fabric.
  • When cleaning floors use a DI water and isopropyl alcohol mixture. Do not wax or buff floors, as this can contaminate the room. Generally, you can apply the same rules to cleaning the floor as you can the walls in a cleanroom, except using an edge-less string mop instead of a flat mop or self-wringing sponge. It is also highly recommended to use an autoclavable bucket and wringer.
  • To make sure that your room continuously operates at maximum efficiency, it's best to establish Standard Operating Procedures (SOP's) that fit your room. Train your personnel in proper cleanroom protocol and establishing a good housekeeping and preventative program to ensure that your room is held to its highest possible operating standards. Also make sure you staff has been trained with the best maintenance practices and create a regular maintenance schedule, which is imperative for any critical environment. Without such a plans and procedures, there is a high risk level of potential pollutants that can ruin the sterility of the environment.